Fluorescent boron and nitrogen co-doped carbon dots with high quantum yield for the detection of nimesulide and fluorescence staining

In this work, we firstly developed a new rapid detection method of nimesulide (Nim) based on the boron and nitrogen co-doped carbon dots (B,N-CDs) as the fluorescence probe. The B,N-CDs were prepared by a facile hydrothermal treatment using ammonium citrate and bis(pinacolato)diboron as precursors. The as-prepared B,N-CDs were mono-dispersed with an average diameter of 3.3 nm, and exhibited good stability and strong fluorescence emission with a high quantum yield of 68.89%. The fluorescence of B,N-CDs was obviously quenched with the addition of Nim. A good linear relationship between ln (F0/F) and the concentration of Nim was obtained in the range of 0–100 μM, and the limit of detection was 125 nM. Furthermore, the proposed analysis method was successfully applied for the detection of Nim in pharmaceutical samples and recoveries ranged from 94.60%–96.73%. More remarkably, it was further found that the as-prepared B,N-CDs displayed bright blue solid-state fluorescence, exhibiting potential application in invisible fluorescent ink for anti-counterfeiting and fluorescent dye.